Swivel electric attachment plug



FIG. 4

J. A. SHERMAN Filed 001:. 15, 1936 FIG. I

INVENTOR JOHN A. SHERMAN ATTORNEY Feb. 7, 1939.

swIvEL ELECTRIC ATTACHMENT PLUG hama Fb..1,1a3a

UNITED STATES PATENT OFFICE I i 2.14am

9T. mmc A, ENUG 0302' 15. 193., sl'lll N0. 105,854

ICIaim.

(CL ITS-324) This invention relates to a swivel electric attachment plug, and has for an object to provide an improved electric attachment plug which can be assembled in any direction of rotation instead of having two xed post contacts which mustbe exactly matched up before the male and female plug and socket portions can be joined together.

A further object of this invention is to provide an electric plug especially adapted for use 1o on the bottom of a. table leg or leg of any other piece of furniture so -that the male plug in the leg may be connected to a female socket in the floor, yet at the same time make it possible for the table or piece of furniture to be placed else- 1I where, when the plug is not to be used. without ruining the male plug, butallowlng it to remain capable of and ready for use at anyl time it is desired to again connect it to the female socket.

A further object of this inventionis to prono vide an electric plug having retractible contact posts in the male element which posts will autovmatically retract into the plug whenever they are forced against an unyielding surface, as

when the plug is located in the leg of a piece of gg furniture, and the furniture is located elsei where than over a proper female receptacle.

With the foregoing and other objects in view, as will hereinafter be apparent, this invention in the construction, combination and arn rangement ofparts, asis hereinafter described, claimed, and illustrated in the accompanying drawing, wherein, y Ilig. i is a partly sectional and partly eleva tional view of the retratible contact form of this invention as applied to a tableleg;

Fig. 2 is a sectional view of the male plug of Fig. 1;

Fig. 3 is a top plan view of Fig. 2; y Fig. 4 is a sectional view of the female socket 0f F18. 1? v' ng. 5 is atop plan view of Fig. 4. There is shown at Il a table, in the'leg Ii of which the male plug portion I2 of this invention has been inserted for cooperation with female receptacle portions Il located in the supporting surface or floor I4. A conduit Il extends from i the male plug I2 through the leg II, which has been hollowed to receive it, to a multiple reeeptacle .plate Il provided, with a plurality of go receptacles Il, thereby providing a suitable outlet for the attachment of table electric appliances such as percolators, waiiie irons, toasters. etc. The female receptacle portion I8 in the door I4 iaconnectedbyaconduit I1.to' anysuitable u source of electrical energy.

The male plug I2 comprises an insulating body member I9 having a central counterbore 20 extending therethrough for a retractible central contact post 2i. This post 2l is provided with collar 22 adapted to be held in abutting relation 5 with the shoulder 23 of the counterbore 20 by a fairly strong compression spring 24,the other end of the lspringresting against an externally threaded nut 2B at'the end of the counterbore 20, this nut 25 being centrally apertured to permit 10 the contact post 2i to'pass freely therethrough, while a screw 26 in the end of the post 2i provides a means for securing one-of the leads 21 of the conduit I5 thereto.

A second retractible contact post 28 is located 15 adjacent one side of the body I9 in an aperture 29 extending completely therethrough. This contact post 28 is provided with a contact head Il) mounted on a stem JI, a compression spring I2 resting against the shoulder I3 on the top of 20 the head 90 and against a countersunk plate I4 having an aperture through which the end of the stem may move freely. This plate 94 is provided with a screw l5 for connecting the other lead 26 of conduit 35 thereto. The end of the g5 stem 3i is held from being lost through the aperture in the plate 84 by any suitable means, as by peening over the end, for instance.

The female receptacle Il comprises an insulating body 31 having a central counterbore 3l in .n which is located a spring clip contact 39 provided with a screw 39' for connecting it to one of the leads 40 of the conduit I1. The central contact post 2i of the male plug I2 is provided with a ball head 4| connected to the body of the g5 post 2i by areduced neck 42 thereby enabling the female spring clip contact 39 to grip it firmly.

A second contact on the female receptacle comprises a ring plate 43 having a radius equal to the distance of the contact 29 from the central 40 contact 2i of the male plug I2. The contact ring plate 43 is held in countersunk relation on the end of the receptacle Il by a plurality of countersunk screws 44 and against the anged end 45 of a nger 46 extending through the body 31 to another flanged end 41 having a screw 48 threaded therethrough for securing the other lead 49 of conduit I1 thereto.

In operation., the compression spring 24 is stronger than the spring clip contact 29, so thaty so when the table leg II is properly placed over the receptacle Il in the iloor I4, the contact head 4I enters the spring clip contact 29 and isflrmly held therein to make a good electrical contact therethrough. Meantime, the contact head 3l of the second contact post 29 is yleldably held against the contact ring plate 43 to complete the circuit, for so long as the head 4i is in the spring clip contact 39, the contact head 30 will press against some part of the circumference of the contact plate ring 43. Should it be necessary to move the table I0 to a location where no female receptacle I3 is available, the table may be placed anywhere without ruining the male receptacle permanently placed in its leg, for both contact posts therein will merely retract into the plug and the space therebehind, ready to be put purposes without the payment of any royalties thereon or therefor.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

A swivel electric attachment plug comprising a male plug portion and a female plug receptacle portion, the male plug portion having a central aperture therethrough, a contact post through said vcentral aperture, a second contact post extending through a second aperture adiacent the side of the male plug, the female plug receptacle portion having a spring clip contact adapted to receive the male contact t post therein, and a spring contact ring plate against which the second contact post V.of the male plug is adapted to bear. said second contact post having a contact head retractible to entirely enter within the body of the plug, and means yieldably urging said head out of the body, said central aperture in of the counterbore and extend the contact postv beyond the plug, said central contact being retractible against said spring to entirely enter within said plug.`

JOHN A. SHERMAN.- 

